/*
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import LRUCache from './LRUCache.js'

// A cache for frequently used country-specific regular expressions. Set to 32 to cover ~2-3
// countries being used for the same doc with ~10 patterns for each country. Some pages will have
// a lot more countries in use, but typically fewer numbers for each so expanding the cache for
// that use-case won't have a lot of benefit.
export default class RegExpCache {
	constructor(size) {
		this.cache = new LRUCache(size)
	}

	getPatternForRegExp(pattern) {
		let regExp = this.cache.get(pattern)
		if (!regExp) {
			regExp = new RegExp('^' + pattern)
			this.cache.put(pattern, regExp)
		}
		return regExp
	}
}